Add a search bar
@swilmet
Submitted by Sébastien Wilmet Link to original bug (#761182)
Description
With the PeasGtkPluginManagerView, it is not convenient to search through the list of plugins.
For example if there is an "Embedded Terminal" plugin, a user might have some difficulties to find it if she scrolls at the T letter or search "term" with the built-in GtkTreeView search with Ctrl+F.
So a search bar would be nice. It would search in the names and descriptions of the plugins, and the GtkTreeView would show only plugins that match the search.